And yet another item on the iPad? Are we serious? Yes, we are, since this one is about something that even geeks who aren't interested in the iPad itself should find intriguing. Steve Jobs said yesterday that the iPad is powered by an Apple A4 processor, but contrary to what many seem to think - it wasn't designed in-house at all.

Very much so. Although since Apple's website describe it as a "1GHz Apple A4 custom-designed, high-performance, low-power system-on-a-chip", I can see how people might be under the impression it was done completely in-house.

I'm guessing that the "custom designed" part refers to the integration work done by Apple, the "system on a chip" part.

Designing a new architecture is incredibly difficult. This shouldn't be a surprise to anyone who knows that. New Chip architectures are going to be increasingly rare due to the insanely high startup costs.